html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  min-height: 100vh;
  overflow-x: hidden; /* 가로 스크롤만 제거 */
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  text-align: center;
  padding: 15px;
  box-sizing: border-box;
  background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 50%, #cbd5e1 100%);
  min-height: 100vh;
  position: relative;
}

body::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: 
    radial-gradient(circle at 30% 20%, rgba(148, 163, 184, 0.1) 0%, transparent 50%),
    radial-gradient(circle at 70% 80%, rgba(203, 213, 225, 0.08) 0%, transparent 50%);
  pointer-events: none;
  z-index: -1;
}

body::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: 
    linear-gradient(90deg, transparent 99%, rgba(148, 163, 184, 0.02) 100%),
    linear-gradient(0deg, transparent 99%, rgba(148, 163, 184, 0.02) 100%);
  background-size: 100px 100px;
  pointer-events: none;
  z-index: -1;
}

header {
  margin-bottom: 15px;
}

h1 {
  font-size: 2.2rem;
  margin-bottom: 8px;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  color: #334155;
  font-weight: 800;
  letter-spacing: -0.025em;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

.subtitle {
  font-size: 0.95rem;
  color: #64748b;
  margin: 0;
  font-weight: 500;
}

/* 게임 설명 섹션 스타일 */
.game-description {
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(10px);
  border-radius: 20px;
  padding: 25px;
  margin: 20px 0;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  max-width: 800px;
  width: 100%;
}

.game-description h2 {
  color: #334155;
  font-size: 1.5rem;
  margin-bottom: 20px;
  font-weight: 700;
}

.description-content {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 25px;
}

.step {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 15px;
  background: rgba(102, 126, 234, 0.1);
  border-radius: 12px;
  border-left: 4px solid #667eea;
}

.step-number {
  background: #667eea;
  color: white;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.75rem;
  flex-shrink: 0;
}

.step p {
  margin: 0;
  color: #475569;
  font-weight: 500;
  font-size: 0.85rem;
  line-height: 1.3;
}

.features h3 {
  color: #334155;
  font-size: 1.2rem;
  margin-bottom: 15px;
  font-weight: 600;
}

.features ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 10px;
}

.features li {
  padding: 10px 15px;
  background: rgba(34, 197, 94, 0.1);
  border-radius: 8px;
  color: #166534;
  font-weight: 500;
  font-size: 0.9rem;
}

main {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
  max-width: 800px;
  margin: 0 auto;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(90px, 1fr));
  justify-items: center;
  gap: 15px;
  width: 100%;
  max-width: 800px;
  padding: 25px;
  border-radius: 24px;
  box-sizing: border-box;
  background: transparent;
  position: relative;
}

.grid::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(20px);
  border-radius: 24px;
  border: 1px solid rgba(255, 255, 255, 0.3);
  z-index: -1;
}

.item {
  display: flex;
  flex-direction: column;
  align-items: center;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  z-index: 1;
  will-change: transform;
}

.item:hover {
  transform: translateY(-4px);
}

.item img {
  width: 100%;
  cursor: pointer;
  border: 3px solid transparent;
  border-radius: 16px;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  background: white;
  padding: 8px;
  box-sizing: border-box;
  will-change: transform;
}

.item img:hover {
  transform: scale(1.05);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.15);
  border-color: #e2e8f0;
}

.item img.selected {
  border-color: #10b981;
  box-shadow: 0 0 0 4px rgba(16, 185, 129, 0.2), 0 8px 25px rgba(16, 185, 129, 0.3);
  transform: scale(1.02);
}

.caption {
  margin-top: 10px;
  font-size: 0.85rem;
  font-weight: 600;
  color: #475569;
  text-align: center;
  line-height: 1.2;
}

button {
  padding: 16px 32px;
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  margin: 25px 0;
  background: linear-gradient(135deg, #10b981 0%, #059669 100%);
  color: white;
  border: none;
  border-radius: 16px;
  box-shadow: 0 4px 20px rgba(16, 185, 129, 0.3);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  width: 90%;
  max-width: 350px;
  position: relative;
  overflow: hidden;
  letter-spacing: 0.025em;
  will-change: transform;
}

button::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: left 0.6s;
}

button:hover::before {
  left: 100%;
}

button:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(16, 185, 129, 0.4);
}

button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
  background: #94a3b8;
}

#race-container {
  position: relative;
  width: 100%;
  max-width: 800px;
  margin: 20px auto;
  overflow: hidden;
  border-radius: 0;
  box-sizing: border-box;
  box-shadow: none;
  background: transparent;
  backdrop-filter: none;
  border: none;
}

/* 개별 트랙 */
.track {
  position: absolute;
  left: 0;
  width: 100%;
  background-repeat: repeat-x;
  background-position: 0 center;
  background-size: auto 100%;
  border: none;
  border-radius: 0;
  transition: all 0.3s ease;
  will-change: background-position;
  overflow: hidden;
}

.track:first-child {
  border-top-left-radius: 0;
  border-top-right-radius: 0;
}

.track:last-child {
  border-bottom: none;
  border-bottom-left-radius: 0;
  border-bottom-right-radius: 0;
}

/* 트랙 배경을 감싸는 내부 컨테이너 - 제거 */
.runner {
  position: absolute;
  display: flex;
  align-items: center;
  padding-left: 15px;
  will-change: transform;
  transition: transform 0.1s ease-out;
  box-sizing: border-box;
}

.runner img {
  max-width: 12vw;
  min-width: 40px;
  transition: transform 0.2s ease-in-out;
  filter: drop-shadow(2px 2px 8px rgba(0, 0, 0, 0.2));
  will-change: transform;
}

.runner.jump img {
  animation: jump 0.6s cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

/* 넘어짐 애니메이션 */
.runner.fallen img {
  animation: fall 1s ease-in-out 0;
  transform: rotate(90deg);
}

@keyframes fall {
  0% { 
    transform: translateY(0) rotate(0deg); 
  }
  25% { 
    transform: translateY(10px) rotate(25deg); 
  }
  50% { 
    transform: translateY(20px) rotate(60deg); 
  }
  75% { 
    transform: translateY(18px) rotate(80deg); 
  }
  100% { 
    transform: translateY(0) rotate(90deg); 
  }
}

@keyframes jump {
  0% { transform: translateY(0) scale(1); }
  50% { transform: translateY(-20px) scale(1.15); }
  100% { transform: translateY(0) scale(1); }
}

/* 순위 (왼쪽, 흰색+테두리) */
.rank {
  position: absolute;
  left: -45px;
  top: 50%;
  transform: translateY(-50%);
  color: #fff;
  font-weight: bold;
  text-align: right;
  min-width: 45px;
  opacity: 0;
  text-shadow:
    -1px -1px 0 #000,
     1px -1px 0 #000,
    -1px  1px 0 #000,
     1px  1px 0 #000;
  font-size: 1.1em;
  transition: opacity 0.3s ease;
  will-change: opacity;
}

/* 결과 텍스트 (1위 / 2위 이하) */
.winner {
  font-size: 1.6rem;
  font-weight: bold;
  margin-bottom: 15px;
  color: #1e293b;
  text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.1);
}

.others {
  font-size: 1.05rem;
  color: #475569;
  line-height: 1.6;
  text-align: left;
  margin-bottom: 20px;
  font-weight: 500;
}

/* 결과 오버레이: 전체 화면을 덮는 반투명 레이어 */
#result-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(255, 255, 255, 0.85);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  border: 0;
  border-radius: 0;
  z-index: 1000;
  padding: 20px;
  box-sizing: border-box;
  box-shadow: none;
}

/* 배경 오버레이 추가 */
.result-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.3);
  z-index: 999;
}

/* 결과 버튼 스타일 유지 */
#result-overlay button {
  margin-top: 20px;
  padding: 14px 28px;
  background: linear-gradient(135deg, #10b981, #059669);
  color: #fff;
  border: none;
  border-radius: 12px;
  cursor: pointer;
  font-weight: 600;
  transition: all 0.3s ease;
}

#result-overlay button:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(16, 185, 129, 0.4);
}

.boost-icon {
  position: absolute;
  right: 0;
  top: 50%;
  transform: translate(15px,-50%) scale(0.8);
  width: 32px; height: 32px;
  pointer-events: none;
  animation: boost-flash 0.7s ease-out;
  filter: drop-shadow(2px 2px 6px rgba(0, 0, 0, 0.3));
  will-change: transform, opacity;
}

@keyframes boost-flash {
  0%   { opacity: 1; transform: translate(15px,-50%) scale(1.4); }
  50%  { opacity: 0.9; transform: translate(15px,-50%) scale(1.2); }
  100% { opacity: 0; transform: translate(15px,-50%) scale(0.8); }
}

footer {
  display: block;
  margin: 10px auto 0 auto;
  padding: 20px;
  font-size: 0.9rem;
  color: #64748b;
  border-top: 1px solid rgba(0, 0, 0, 0.1);
  width: 100%;
  max-width: 800px;
  text-align: center;
  background: rgba(255, 255, 255, 0.6);
  backdrop-filter: blur(10px);
  border-radius: 16px;
  box-sizing: border-box;
}

.footer-content p {
  margin: 6px 0;
}

.footer-content .contact a {
  color: #10b981;
  text-decoration: none;
  transition: color 0.3s ease;
  font-weight: 500;
}

.footer-content .contact a:hover {
  color: #059669;
  text-decoration: underline;
}

.footer-content .legal-links {
  margin-top: 10px;
}

.footer-content .legal-links a {
  color: #94a3b8;
  text-decoration: none;
  font-size: 0.85rem;
  transition: color 0.3s ease;
}

.footer-content .legal-links a:hover {
  color: #64748b;
  text-decoration: underline;
}

/* 반응형 디자인 개선 */
@media (max-width: 768px) {
  body {
    padding: 10px;
  }
  
  header {
    margin-bottom: 10px;
  }
  
  h1 {
    font-size: 1.8rem;
    margin-bottom: 6px;
  }
  
  .subtitle {
    font-size: 0.85rem;
  }
  
  .grid {
    grid-template-columns: repeat(auto-fit, minmax(80px, 1fr));
    gap: 12px;
    padding: 20px;
    border-radius: 20px;
  }
  
  button {
    font-size: 1rem;
    padding: 14px 28px;
  }
  
  #race-container {
    max-width: 95%;
    border-radius: 0;
  }
}

@media (max-width: 480px) {
  h1 {
    font-size: 1.5rem;
  }
  
  .subtitle {
    font-size: 0.8rem;
  }
  
  .grid {
    grid-template-columns: repeat(auto-fit, minmax(70px, 1fr));
    gap: 10px;
    padding: 15px;
  }
  
  .item img {
    border-radius: 12px;
    padding: 6px;
  }
  
  button {
    font-size: 0.95rem;
    padding: 12px 24px;
  }
  
  footer {
    font-size: 0.85rem;
    padding: 15px;
  }
  
  /* 작은 화면에서도 내용에 따라 높이가 결정되도록 유지 */
}

/* 다크 모드 지원 */
@media (prefers-color-scheme: dark) {
  body {
    background: #0f172a;
  }
  
  body::before {
    background: 
      radial-gradient(circle at 20% 80%, rgba(120, 119, 198, 0.2) 0%, transparent 50%),
      radial-gradient(circle at 80% 20%, rgba(255, 119, 198, 0.2) 0%, transparent 50%),
      radial-gradient(circle at 40% 40%, rgba(120, 219, 255, 0.15) 0%, transparent 50%);
  }
  
  h1 {
    color: #f1f5f9;
  }
  
  .subtitle {
    color: #94a3b8;
  }
  
  .grid::before {
    background: rgba(30, 41, 59, 0.8);
    border: 1px solid rgba(255, 255, 255, 0.1);
  }
  
  .caption {
    color: #cbd5e1;
  }
  
  /* 레이스 컨테이너는 투명 유지 (작은 참가 수에서 배경 오버레이 방지) */
  #race-container {
    background: transparent;
    border: none;
  }
  
  footer {
    background: rgba(30, 41, 59, 0.8);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: #94a3b8;
  }
}

/* 게임 팁 스타일 */
.game-tip {
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(10px);
  border-radius: 15px;
  padding: 15px 20px;
  margin-top: 20px;
  text-align: center;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  transition: all 0.3s ease;
}

.game-tip:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

.tip-icon {
  font-size: 20px;
  margin-right: 8px;
  display: inline-block;
  animation: tipGlow 2s ease-in-out infinite alternate;
}

.tip-text {
  font-size: 14px;
  color: #334155;
  font-weight: 500;
  line-height: 1.4;
}

@keyframes tipGlow {
  0% { opacity: 0.7; transform: scale(1); }
  100% { opacity: 1; transform: scale(1.1); }
}

.info-section {
  max-width: 800px;
  margin: 20px auto 10px;
  padding: 0 16px;
  font-size: 0.95rem;
  line-height: 1.6;
  color: #1e293b; /* 어두운 파란 계열로 가독성 확보 */
  text-align: left;
}

@media (prefers-color-scheme: dark) {
  .info-section {
    color: #e2e8f0;
  }
}

.hidden {
  display: none !important;
}

/* 게임 설명 버튼 스타일 */
.help-btn {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border: none;
  padding: 12px 24px;
  border-radius: 25px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  margin: 20px 0 10px 0;
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
  transition: all 0.3s ease;
}

.help-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
}

/* 모달 팝업 스타일 */
.modal {
  display: none;
  position: fixed;
  z-index: 1000;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(5px);
}

.modal-content {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  margin: 8% auto;
  padding: 0;
  border-radius: 20px;
  width: 90%;
  max-width: 500px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
  animation: modalSlideIn 0.3s ease-out;
}

@keyframes modalSlideIn {
  from {
    opacity: 0;
    transform: translateY(-50px) scale(0.9);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 25px 30px 20px;
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.modal-header h2 {
  margin: 0;
  color: #334155;
  font-size: 1.5rem;
  font-weight: 700;
}

.close {
  color: #94a3b8;
  font-size: 28px;
  font-weight: bold;
  cursor: pointer;
  transition: color 0.3s ease;
}

.close:hover {
  color: #64748b;
}

.modal-body {
  padding: 30px;
}